#btn{
    position: fixed;
    z-index: 1000;
    right: 10px;
    cursor: pointer;
    /* background-color: tomato;, */
    bottom: 100px;
    width: 50px;
    height: 50px;
    font-family: layui-ico !important;
    font-size: 50px;
    /* background-color: tomato; */
}
#btn:before {
    content: "\e604";
}



